# sample size calculation for 4 groups means

Suppose that I have 4 groups means:18,13,16,10, and 4 standard deviation:10,9,9,8, and α=0.05，β=0.1, how many samples do I need?

I'm trying to calculate the sample size using pwr package in R. But I don't know how to calculate the f in pwr.anova.test().

Also, if I use power.anova.test, I don't know how to calculate the within.var.

Anyone can help? Thank you very much!